Baldwin Boxall M2120E Operating Instructions Manual

IM2120E

Issue 2 28/01/2008

ECR 2043

M2120E Amplifier

Operating Instructions

Baldwin Boxall Communications Ltd.

Wealden Industrial Estate, Farningham Road

Crowborough, East Sussex, TN6 2JR
Telephone: [phone]

Fax: [phone]

Website: www.baldwinbox all.c o.uk
Email: mail@baldwinb oxall .co.uk

SAFETY

IMPORTANT NOTES - DO’S AND DON’TS

Ventilation

Always ensure adequate ventilation to the amplifier.
Do not obstruct the ventilation holes in the cover or base.
Should the amplifier exceed its safe operating temperature it will automatically reduce its volume to a
safe level thus allowing it to cool. Once cooled it will operate normally without manual resetting.

AC Power Input - Danger High Voltage
Only connect to an AC 50-60 Hz 230V supply using the lead assembly supplied or an equivalent type
with a suitable IEC connector.
Always ensure that the amplifier is earthed.
Always unplug the power before removing the top cover.

100V Loudspeaker Output - Danger High Voltage
Ensure that the loudspeaker connections are suitably protected and cannot be touched. Always replace
output plug insulated covers.

Always ensure that the total speaker load does not exceed the rating of the amplifier used.
If unsure use an impedance meter to measure the unknown load.
Using a multimeter selected to the resistance range ensure that the speaker line is not connected to
earth.

Moisture
Do not allow water to come in contact with the amplifier and its external connections.

Cable Types
Always ensure that the correct cable type is used for the signal level.
A twin screened cable should be used for balanced inputs operating at mic or line level. Zone
selection and access control cables do not generally require screening and should not share the same
screen as the balanced input.

Loudspeaker output cables should be rated in excess of 100V and the cross sectional area to suit the
load without excessive power loss.
Always ensure that output cables are kept as far away from input cables as possible reducing the risk
of instability.

Fuses
Always replace using the correct rating and type to ensure safe operation.

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Page 2 of 8

M2120E USER INSTRUCTIONS

The M2120E is an integrated 5 input 120 Watt free standing or rack-mounting amplifier powered from a 230
Volt AC supply. Each of the 5 inputs has separate volume, bass and treble controls.
An output level 4 bar LED display indicates at 5% 25% 50% and 100% output.

Both low impedance and 100 Volt line outputs are available on a 4 pin Speakon connector, (pair 1+ and 1­being 100V and pair 2+ and 2- being low impedance), see fig 1 for connection details. The low impedance
output is unbalanced ref to ground, suitable for driving 4 off 8 Ohm speakers connected in parallel or any other
combination providing that the resulting imped ance is no lower than 2 Ohms.

The 100 Volt line output is derived from a transformer that provides a fully floating output.
If a balanced output is required the centre tap may be connected to ground via a link on the Speakon printed
circuit board, see fig 2.

The power output stage is protected against overload conditions, i.e. short circuits etc., by sensing the current
and voltage and presenting this error signal to a drive limiter circuit. Should the amplifier be su bjected to an
abnormal load the input to the power amplifier is limited to a safe level. Over temperature protection is also
provided using a sensor attached to the output stage heatsink. Should the temperature exceed 90 C then the
input signal is reduced to a low level preventing permanent damage to the amplifier.

Each of the 5 inputs can be set to either balanced Mic sensitivity (20-600 Ohm, 0.6mV) or balanced Line
sensitivity (80mV) using the relevant DIL switch on the rear panel. These switches also control the Phantom
Power facility (20V DC) for each input.
See fig 3 for details on these switch settings.

Input 5 can use either 2 Phono connectors to enable a compact disk or cassette tape machine to be easily
connected, or if this feature is not required then a DIL switch is provided to switch the input to the XLR
connector.
See fig 3 for details on this switch setting.

Inputs 1 to 4 are provided with input gating and to use any input the relevant input access must be closed to 0
Volts, even if priority is not selected.
When priority is selected using the DIL switches on the rear panel, the relevant input will override all
descending; i.e. input 1 will override inputs 2, 3, 4 and 5.
See fig 3 for details on these switch settings.
Please note that input 5 is permanently accessed and therefore has no input access connection.

The open collector busy output will become active i.e. conduct to 0 Volts to operate relays, busy indicators etc,
only if the priority is selected and input accessed. The busy output is protected by a 500mA self resetable fuse.
A +24 Volt output is provided to power auxiliary equipment and is protected by a 1 Amp self resetable fuse.

An OPT 33 chime module may be fitted to sound when an input is accessed.
Please note that the chime will only sound with priority selected on the desired input or by closing the chime
trigger input to ground.
The chime pre-set volume and DIL switch to select 1, 2, or 3 notes are mounted on the OPT 33.

Optional signal processing (i.e. Bose loudspeaker equaliser OPTEQ) may be incorporated using the internal
connector provided, see fig 5 for details on mounting this option.

Additional external equipment (e.g. a graphic equaliser) can be inserted between the preamplifiers and power
amplifier by removing the jumper link from the POWER AMP INPUT and PRE AMP OUT phono connectors
on the rear panel.
The external equipment should have an input impedance greater than 5K Ohms and output impedance lower
than 2K Ohms with a nominal level of 800 mV.

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M2120E Integrated Technical Specification

Rated output power
100V line 230V AC supply

120W 83 Ohms
THD 1 kHz rated output
Aux input 230V AC supply
Typical output power 1% THD
Aux input 230V AC supply

Less than 0.5% typically 0.2%

100V line 150W 66 Ohms

Low Z - 80W 4 Ohms

Low Z - 130W 2 Ohms
Output regulation (1 kHz 100V line) Better than 1dB
Output voltages obtainable
(Pin selection)

100V & low impedance
Supply voltage AC 220 – 240V 50 – 60 Hz
Power consumption @ 230V
Quiescent
Rated output power @ 1kHz
Fuse protection
1 x AC supply 20 x 5mm
2 x DC (amplifier) auto blade type
1 x 24V DC output
1 x DC “Busy” open collector output

1A Self resetable

500mA Self resetable
Aux input phono stereo summed mono
Sensitivity
Frequency response – 3dB
Signal to noise ratio

100mV @ 20K Ohms

Better than 40 Hz – 20 kHz

Better than 80 dB
Tone controls
Bass
Treble

± 12 dB @ 100 Hz

± 12 dB @ 12 kHz
Universal input (line)
Sensitivity
Frequency response – 3dB
Signal to noise ratio

80mV @ 12K balan c ed

Better than 40 Hz – 18 kHz

Better than 70 dB
Universal input (Mic)
Sensitivity

600µV balanced
Input impedance
Without phantom power
With phantom power 20V
Frequency response – 3dB Better than 40 Hz – 18 kHz
Common mode rejection ra ti o
50 Hz – 30 kHz

Better than 60 dB
Signal to noise ratio terminated 200 Ohms Better than 60 dB
LED indicators Output level indicator

5%, 25%, 50% & 100%
Terminations
AC supply input
Aux signal input

3-pin DIN IEC 6A

2 x phono, stereo summed mono
Universal input
Input Access
Loudspeaker output

6-pin screw terminal connector

4-pin Speakon connector
Fan assisted No
Dimensions (mm) (D x W x H) 340 x 430 x 90
Weight 12 kg

18VA

300VA

3.15A(T)
10A(F)

12k Ohms
660 Ohms

3-pin XLR

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Page 4 of 8

SPEAKON LOUDSPEAKER OUTPUT CONNECTIONS

1+

2+

100V

+

0V

0V

100V LINE

LOW Z

1-

2-

SPEAKON LOUDSPEAKER

OUTPUT CONNECTOR

P14

2+

FIG 1

1-2-

1+

BALLANCED 100V LINE SELECTION

FIG 2

C36C37C38 C35

ADD LINK TO EARTH PC1210B

OUTPUT CENTRE TAP

CT-LK

FIG 3

FIG 4

GND BK Y BL RD W G

DIL SWITCH (1 PER INPUT)

XLR or PHONO - INPUT 5 ONLY
ON = XLR MIC/LINE

OFF = PHONO 100mV

PRIORIT Y INPUTS 1 TO 4
ON = THIS INPUT WILL

OVERRIDE DESCENDING INPUTS
OFF = THIS INPUT WILL NOT
OVERRIDE DESCENDING INPUTS
AND WILL MIX

XLR INPUT CONNECTIONS

1234

XLR SENSITIVITY
ON = MIC 0.6mV.

OFF = LINE 80mV.
XLR PHANTOM POW ER

BOTH ON = 20V MIC PHANTOM POWER
BOTH OFF = NO PHANTOM POWER

ON

PUSH

BALANCED

INPUT

GROUND

12

3

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Page 5 of 8

Fig 5: Location and Orientation of Connectors for OPT33 and OPTEQ

MPORTANT NO

T

PC1210

HEATSINK

D28

R136

C118

+

C98

INSERT 4 x PILLARS FROM SOLDER SIDE

REG2

R114

C121

U13

C110

R111

R123

R1

C117

E

R98

R95ZD25

R137

C103

C115

P10

R113

R74

+

C120

VR6

MASTER

OPTION

R138

C119

C72

C116 TR8

U10

C80 C81

C82 C129

R75

R73

P9

U9

R62

C68

R61

VR5VR4

R146

P13

C71

C69

R60

C70

FRONT

I

PLEASE ENSURE THE CORRECT

ORIENTATION OF THE OPT EQ CONNECTOR

INCORRECT FITMENT WILL RESULT

DAMMAGE TO THE EQUIPMENT.

PLUG DOWN ONTO P10 ON M2120E BOARD

C83

R100

HERE

OPT33

MOUNTED

C75 C76 C74 C73 C77

C65

U7

VOLUME I/P4 VOLUME I/P5

R57

FIG 5

COMPONENT SIDE DOWN

OPT E Q OPTION

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Page 6 of 8

M2120E BLOCK DIAGRAM

OUTPUT

100V LINE

OUTPUT

TRANSFORMER

OUTPUT

LEVEL

INDICATOR

100%

50%

25%

5%

OUTPUT

MUTE

RELAY

120W

POWER

AMPLIFIER

OPTION

SOCKET

IN

800mV

PHONO

0V

OUT

0V

0V

VOLUME

MASTER

1+ 1-

SPEAKON

CONNECTOR

PROVIDING

PRIORITY LOGIC

CASCADE OR MIXING

LOW Z0VOUTPUT

2+ 2-

+24V

INPUT1

INPUT2

INPUT3

ACCESS

1

2

3VOLUME

INPUT GATING & B US Y

BUSY

CHIME

COMMON

INPUT4

COM

+24V

0V

BUSY

4

CHIME

MAINS

PSU

OPT33

CHIME

FUSE

+33V

230V MAINS I/P

LEN

0V

CHIME IS ONLY SELECTED

WHEN PRIORITY IS SELECTED

AC 50Hz - 60Hz

MAINS

SWITCH

-33V

MIXER

EARTH

VIRTUAL

BASS TREBLE

1

+20V

1

PHANTOM

POWE R MIC/LINE

0V

231

600uV MIC

80mV LINE

INPUT 1

XLR

BASS TREBLE

VOLUME

INPUT 1

0V

2

2

+20V

PHANTOM

POWE R MIC/LINE

0V

231

600uV MIC

80mV LINE

INPUT 2

XLR

BASS TREBLE

VOLUME

INPUT 2

0V

3

3

+20V

PHANTOM

POWE R MIC/LINE

0V

231

INPUT 3

600uV MIC

80mV LINE

XLR

BASS TREBLE

INPUT 3

0V

4

4

+20V

PHANTOM

POWE R MIC/LINE

0V

231

600uV MIC

80mV LINE

INPUT 4

XLR

BASS TREBLE

VOLUME

INPUT 4

0V

5

+20V

PHANTOM

5

5

POWE R MIC/LINE

0V

231

600uV MIC

80mV LINE

INPUT 5

VOLUME

INPUT 5
0V

0V

0V

XLR

AUX

PHONO

Issue 2

Page 7 of 8

M2120E Front and Rear Panel Illustration

C O M M U N I C A T I O N S

output level

0

0

5

5% 25% 50% 100%

+

5

+

euroamp

masterinput 5input 4input 3input 2inpu t 1

010

010

+

0

5

+

0

+

0

5

+

0

+

0

5

+

0

+

0

5

+

0

bass bass bass bass basstreble treble treble treble treble

010

010

010

010

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Page 8 of 8